High output fan wheel

Abstract

A high output bent fin type of fan wheel for use in appliances such as but not limited to microwave ovens. The fan wheel is made by single 90-degree bends for each fan blade relative to the flat mounting plate. Unique to fan wheel is the large fan blade surface area in relation to the total area of the metal used in wheel.

What is claimed is: 
     
         1 . A centrifugal fan for an oven having a fan motor, wherein said fan is made from a single sheet of metal using a bent fin-type plurality of fan blades, said fan comprising:
 a mounting plate having a plate surface area, wherein said mounting plate is used to connect said fan to the fan motor;   a plurality of fan blades wherein each blade has a tip and wherein said plurality of fan blades having a fan blade surface area, wherein the fan blade surface area is greater than the plate surface area of said mounting plate; and wherein each of said plurality of fan blades is made by a single 90 degree bend relative to said mounting plate; and wherein each blade of said plurality of fan blades is inclined backward at a predetermined angle.   
     
     
         2 . The centrifugal fan of  claim 1  wherein the predetermined angle is 39 degrees. 
     
     
         3 . The centrifugal fan of  claim 1  further comprising an outer ring attached to the tips of said plurality of fan blades in order to stabilize each blade at the proper 90 degrees. 
     
     
         4 . The centrifugal fan of  claim 1  is made from stainless steel which allows for thinner, less expensive and lighter weight materials. 
     
     
         5 . The centrifugal fan of  claim 1  wherein the number of said fan blades is an odd number. 
     
     
         6 . The centrifugal fan of  claim 5  where the odd number of blades is 7.